1. Field of the Invention
The present invention relates to a method of diagnosing a lubricated portion and a system of diagnosing a lubricated portion, and more particularly, to a method of diagnosing a lubricated portion and a system of diagnosing a lubricated portion which can precisely measure a metal concentration in a lubricating oil and can diagnose accurately a state of the lubricated portion on the basis of a value of measurement.
2. Description of the Prior Art
Conventionally, as a method of diagnosing a lubricated portion, there has been known a so-called SOAP method (Spectrometric Oil Analysis Program), and this method is a method of diagnosing a state of the lubricated portion comprising the steps of diluting a lubricating oil picked up from the lubricated portion by an organic solvent so as to prepare a sample oil, exciting a metal particle in the sample oil by a plasma or the like so as to emit light, measuring a wavelength and a strength of an atomic spectrum line obtained by separating the light so as to measure the metal concentration, and diagnosing the state of the lubricated portion the basis of a rate of change of the metal concentration in accordance with a time elapse. In accordance with this method, there can be obtained an advantage that a state of lubrication and a state of wear can be easily diagnosed without disassembling and inspecting a structure in the lubricated portion.
However, in accordance with the conventional method of diagnosing the lubricated portion, in the case that a large-diameter metal particle having a particle diameter larger than 10 μm is contained in the picked-up lubricating oil, the large-diameter metal particle is not excited, so that it is impossible to measure an accurate value of the metal concentration in the lubricating oil. As a result, it is impossible to accurately diagnose the state of the lubricated portion. In other words, the conventional method of diagnosing the lubricated portion is only a rough standard for diagnosing a certain degree of state of the lubricated portion.